乌兰坝紫萼藓(紫萼藓科)成熟孢子体的发现

Discovery of Mature Sporophytes of Grimmia ulaandamana (Grimmiaceae)

摘要:

最近在中国内蒙古发现了乌兰坝紫萼藓(Grimmia ulaandamana J. Muñoz, C. Feng, X.L. Bai & J. Kou)的可育植株，介绍了乌兰坝紫萼藓成熟孢子体、雌株和雄株的特征。孢子体的孢蒴长于蒴柄，蒴柄弯曲，蒴壶表面具纵褶，蒴壁中部表皮细胞厚壁，环带细胞方形或短长方形，蒴盖有喙；蒴齿具疣并在上部分叉，蒴齿在基部分开，蒴齿基部低于蒴壶口，蒴壁表皮细胞和蒴齿之间存在一层小型细胞，蒴齿骨小梁在基部1/3处强烈凸出；蒴帽基部完整。最内侧雌苞叶较茎叶大。乌兰坝紫萼藓具有重要的形态特征变异，可育植株与相似种直叶紫萼藓(G. elatior)易于区分。对乌兰坝紫萼藓进行了全面的描述并配显微图，探讨了孢子体对确定其系统发育位置的重要性。

Abstract:

The fertile plants of Grimmia ulaandamana J. Muñoz, C. Feng, X.L. Bai & J. Kou were recently discovered in Inner Mongolia, China. The characteristics of mature sporophytes, as well as female and male plants were described. The capsule of sporophytes is longer than the arcuate seta, capsular surface with longitudinal wrinkle, epidermal cell wall of central capsule was thick, ring cells square or short rectangular, the opercle with beak. The peristome teeth had papillose and bifurcated at upper part, separated at base, the base of peristome teeth is lower than mouth of capsule. There is a layer of small cells between epidermal cells and peristome teeth, the trabeculae of capsular bones are strongly protruding about 1/3 of the base. Capsular cap base intact. The innermost female bracts are larger the leaves at stem. Grimmia ulaandamana had important morphological variation, the fertile plants could provide more evidence to distinguish from the most similar species G. elatior. The novel description and illustrations of sporophytes were presented, and the phylogenetic significance of sporophytes was discussed.